Despite the advances in brain and central nervous system disorders remains the world’s leading cause of disability. The delivery of drugs to central nervous system remains a challenge for the treatment of nervous system disorders. The major problem faced with drug delivery is the presence of blood brain barrier (BBB). The blood brain barrier (BBB) is an effective membrane that limits the passage of exogenous substance to the central nervous system. Drugs that are effective against CNS diseases must pass through the BBB. Therefore, many drugs developed for the treatment of CNS diseases have been unable to show significant therapeutic effects. Hence, the failure of systemically delivered drugs to effectively treat many diseases have surged the demand for development of drug delivery system.